title: Structure and catalytic mechanism of yeast 4-amino-4-deoxychorismate lyase.
abstract: Saccharomyces cerevisiae Abz2 is a pyridoxal 5'-phosphate (PLP)-dependent lyase that converts 4-amino-4-deoxychorismate (ADC) to para-aminobenzoate and pyruvate. To investigate the catalytic mechanism, we determined the 1.9 Å resolution crystal structure of Abz2 complexed with PLP, representing the first eukaryotic ADC lyase structure. Unlike Escherichia coli ADC lyase, whose dimerization is critical to the formation of the active site, the overall structure of Abz2 displays as a monomer of two domains. At the interdomain cleft, a molecule of cofactor PLP forms a Schiff base with residue Lys-251. Computational simulations defined a basic clamp to orientate the substrate ADC in a proper pose, which was validated by site-directed mutageneses combined with enzymatic activity assays. Altogether, we propose a putative catalytic mechanism of a unique class of monomeric ADC lyases led by yeast Abz2.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei Anhui 230027, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Dai
authors.forename: Chang-Biao
authors.initials: CB
authors.lastname: Chi
authors.forename: Kang
authors.initials: K
authors.lastname: Zhou
authors.forename: Wang
authors.initials: W
authors.lastname: Cheng
authors.forename: Yong-Liang
authors.initials: YL
authors.lastname: Jiang
authors.forename: Yan-Min
authors.initials: YM
authors.lastname: Ren
authors.forename: Ke
authors.initials: K
authors.lastname: Ruan
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Chen
authors.forename: Cong-Zhao
authors.initials: CZ
authors.lastname: Zhou
mesh_terms: D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D007652:Oxo-Acid-Lyases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D029968:Escherichia coli Proteins; D029701:Saccharomyces cerevisiae Proteins; D007652:Oxo-Acid-Lyases; C066600:aminodeoxychorismate lyase
keywords: ADC Lyase; Crystal Structure; Enzyme Mechanisms; Molecular Docking; Pyridoxal Phosphate; Yeast